Explanation
The distance between the centers of the two pupils, adjustable on headsets to optimize the 3D display.
Real-world example
Adjusting the lens spacing on your VR headset to match your eyes (typically 60-70 mm).
Practical applications
- Visual comfort: preventing eye strain, headaches, and blurry vision
- Correct 3D perception: seeing depth and distances as intended
- Optimal sharpness: aligning the lenses with your pupils
- Accessibility: adapting the headset to different facial structures
IPD adjustment methods
Mechanical IPD (wheel/slider)
- Physical adjustment of the distance between the lenses
- Precise adaptation for each user
- Standard on high-end headsets
Example: Quest 3: continuous adjustment wheel from 58 to 71 mm
Software IPD (image offset)
- Digital adjustment with no moving parts
- Less precise, may reduce the effective FOV
- Entry-level headsets
Example: Quest 2: only 3 preset positions
VR scenario
A trainer sets up 10 headsets for a session. Each participant adjusts the IPD to their own facial structure in 5 seconds using the wheel. Result: everyone sees clearly, and nobody leaves with a headache. Small adjustment, big impact.
Why it matters in professional VR
- An incorrectly set IPD guarantees discomfort, even with the best content
- Must be checked every time multiple people share a headset
- Selection criterion: prefer headsets with continuous mechanical IPD adjustment